I'm trying to learn how to use WPF but in the book I'm using it doesn't explain how to expose a custom control to the xaml document in Visual Studio.

Visual Studio has some text about including the namespace but I haven't been able to get it to work.

CustomCanvas Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using Position = WpfApplication1.PositionUInt;

namespace WpfApplication1
{
    /// <summary>
    /// Follow steps 1a or 1b and then 2 to use this custom control in a XAML file.
    ///
    /// Step 1a) Using this custom control in a XAML file that exists in the current project.
    /// Add this XmlNamespace attribute to the root element of the markup file where it is 
    /// to be used:
    ///
    ///     xmlns:MyNamespace="clr-namespace:WpfApplication1"
    ///
    ///
    /// Step 1b) Using this custom control in a XAML file that exists in a different project.
    /// Add this XmlNamespace attribute to the root element of the markup file where it is 
    /// to be used:
    ///
    ///     xmlns:MyNamespace="clr-namespace:WpfApplication1;assembly=WpfApplication1"
    ///
    /// You will also need to add a project reference from the project where the XAML file lives
    /// to this project and Rebuild to avoid compilation errors:
    ///
    ///     Right click on the target project in the Solution Explorer and
    ///     "Add Reference"->"Projects"->[Browse to and select this project]
    ///
    ///
    /// Step 2)
    /// Go ahead and use your control in the XAML file.
    ///
    ///     <MyNamespace:CustomControl1/>
    ///
    /// </summary>
    /// 
    class DrawingCanvas : Canvas
    {
        private List<Visual> visuals = new List<Visual>();
        protected override int VisualChildrenCount
        {
            get
            {
                return visuals.Count;
            }
        }
        protected override Visual GetVisualChild(int index)
        {
            return visuals[index];
        }
        public void AddVisual(Visual visual)
        {
            visuals.Add(visual);
            base.AddVisualChild(visual);
            base.AddLogicalChild(visual);
        }
        public void DeleteVisual(Visual visual)
        {
            visuals.Remove(visual);
            base.RemoveVisualChild(visual);
            base.RemoveLogicalChild(visual);
        }
    }
}

Current basic xaml document, just trying to see how to add the custom control

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">



</Window>
This article has been dead for over six months. Start a new discussion instead.